G93.42 – Megalencephalic leukoencephalopathy with subcortical cysts

ICD-10-CM 2027 diagnosis code · Other disorders of the nervous system

Billable code

ICD-10-CM code G93.42

Code: G93.42 (claims format: G9342)
Description: Megalencephalic leukoencephalopathy with subcortical cysts
Billable: Yes – valid for HIPAA-covered transactions
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 6. Diseases of the nervous system (G00-G99)
Block: G89-G99 Other disorders of the nervous system
Parent codes: G93 › G93.4

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

G93.4 – Other and unspecified encephalopathy

Excludes2 (not included here):

alcoholic encephalopathy (G31.2)
encephalopathy in diseases classified elsewhere (G94)
hypertensive encephalopathy (I67.4)
toxic (metabolic) encephalopathy (G92.8)

Index terms for G93.42

Entries in the ICD-10-CM alphabetic index that lead to this code:

Leukoencephalopathy, megalencephalic, with subcortical cysts

Related codes in G93.4

G93.40 – Encephalopathy, unspecifiedBillable
G93.41 – Metabolic encephalopathyBillable
G93.43 – Leukoencephalopathy with calcifications and cystsBillable
G93.44 – Adult-onset leukodystrophy with axonal spheroidsBillable
G93.45 – Developmental and epileptic encephalopathyBillable
G93.49 – Other encephalopathyBillable

Frequently asked questions

What is ICD-10 code G93.42?

G93.42 is the ICD-10-CM code for megalencephalic leukoencephalopathy with subcortical cysts, in the block G89-G99 (Other disorders of the nervous system).

Is G93.42 a billable code?

Yes. G93.42 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does G93.42 belong to?

It belongs to category G93 – Other disorders of brain.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.